The present invention relates to apparatus for wet treatment of textile material in the form of an endless cloth rope that is circulated through a liquid treating chamber, and more particularly to such an apparatus wherein the cloth rope is fed into a generally horizontal treating chamber in vertical folds to form a cloth plug for effective application of the treating liquid to the textile material as it progresses through the chamber.
In the context of this invention, the term "cloth" encompasses all types of textile materials capable of being handled in rope form, such as woven, knitted, or non-woven and various types of natural and synthetic materials, and the treatment can be dyeing or washing or any other type of liquid treatment.
Machines of this general type are well known in the art and usually include as adjuncts to the generally horizontal liquid treating chamber a cloth return tube above or below the chamber and connected to its ends. A liquid circulating system directs the liquid through the return tube as well as into the treating chamber, with a cloth reel and/or a liquid nozzle for circulating the cloth rope through the treating chamber and the return tube and with a heat exchanger included where needed to raise and maintain the temperature of the treating liquid at some predetermined temperature. These machines are generally capable of treating most fabrics adequately with desirable characteristics of gentle handling of the fabric to avoid damage, minimizing of crease marks and other blemishes that effect quality and low liquor ratios that minimize the amount of treating liquid needed. However, there are limitations in the usefulness of these machines to produce acceptable results with some fabrics, such as lightweight delicate fabrics, and there are limitations in cycle time, such that there has been a desire in the industry to strive for improvement of these characteristics to obtain enhanced and more economical results with all fabrics and in shorter cycle times.
Damage to the fabric being treated due to mechanical handling as the cloth rope is recirculated through the prior art machines prevents use of the machines to treat delicate fabrics or limits the speed at which the machines can be operated so that appreciable damage will not occur. The quality of the treated fabric is adversely affected by improperly treated marks resulting from creases unavoidably formed in the fabric during folding in the formation of the cloth plug and by dripping of condensed liquid from the top of the treating chamber on to the cloth plug, particularly when a portion of the cloth plug is exposed above the level of the treating liquid in the chamber. Further, the cycle time of prior art machines is limited by the ability of a single venturi or jet nozzle, normally located in the return tube at the exit end of the liquid chamber, to impel movement of the cloth rope throughout the entire machine, which limits the speed at which the cloth rope can be circulated and imposes mechanical strain on the cloth rope when increased speeds are attempted.
Typical of the prior art is a machine marketed by Hisaka Works, Ltd., as Model CUT-FL. This machine has a generally horizontal treating chamber through which the cloth rope travels in vertical folds as a plug and is drawn from the chamber and impelled through the return tube by a treating liquid nozzle located in the return tube adjacent the exit end of the treating chamber. This nozzle provides the only cloth impelling device in the system and the only location at which treating liquid is introduced. There is no means for applying liquid to the cloth rope during its progression through the treating chamber and no means is provided to avoid dripping of condensate from the top of the treating chamber onto the plug. A similar machine is shown in Platt International Ltd. U.S. Pat. No. 3,762,189, which, in addition, shows the return tube curved upwards and back on itself at the discharge of the cloth rope into the treating chamber and the tube increases in area to facilitate the passage of the fabric around the curve without objectionable crushing, but this outlet does not provide a full opening of the fabric from the rope form to the plug form as it enters the chamber. This curved discharge end of the cloth tube is modified by the addition of a trumpet in the form of the machine marketed as Platt Longclose Uniflow, which allows for opening of the fabric, but does not positively provide for opening of the fabric as it is formed into vertical folds. Thus, both of these Platt constructions do not minimize substantially the formation of creases during the fold formation. Two generally similar machines are marketed by ATYC of Spain, one is designated at the Rapid Suau S, which has a trumpet shaped flared discharge end to the cloth tube where the cloth is discharged into the treating chamber, and in the Rapid Suau Spiral form of the machine the cloth tube is discharged downwardly from the return tube onto a perforated plate, and in addition there is a series of sprays that spray treating liquid onto the plug in a portion of its travel through the treating chamber, but the spray does not act throughout the extent of the exposed portion and does not act over the surface of the chamber to eliminate dripping. Sprays are also disclosed in Burlington Industries, Inc., U.S. Pat. No. 3,301,026, in which the sprays are used simply to maintain the cloth rope under the level of the treating liquid in the treating chamber, and in Kawasaki U.S. Pat. No. 3,782,138, in which overflow troughs are provided above the cloth plug in the treating chamber for the same purpose. Another prior art example is Krantz U.S. Pat. No. 3,982,411, which discloses a flared discharge of the cloth rope from the return tube into the treating chamber, and also discloses a multiple inlet nozzle through which the treating liquid is injected to impel the cloth rope through the system, but the multiple opening nozzle is at only one location in the machine.